ef 85 f1.2 mk2 ruined my pants

Hi guys,
One of my favourite lenses turned on me, ruined my shirts and my pants. The coating on the back plastic part started dissolving, noticed it was a bit stick for a few weeks... noticed my clothes had spots and streaks, never connected the dots LOL...

Anyhow, I searched for the cause of this, only to come across that others have the same issue, some scrubbed it with 91% alc., I tried it, did not really work, scrubbed it for an hour or so... I finally took it of off the lens, used different solutions, the only thing that worked was paint thinner... cleaned it the best I could, took me another hour or so... my fingers are sore and white from the residue.

The lens is usable now but it it looks kinda bad. Looked around to purchase that part but the only ones available are chinesium...

Anyone working for canon here, can one get the original part any more?

Part number CY3-2154-010


Thank you.